Fix test_subprocess and locale by youknowone · Pull Request #6416 · RustPython/RustPython

youknowone

Walkthrough

Adds runtime input validation: CreateProcess now rejects embedded NUL bytes in optional name and command_line fields; setlocale on Windows gains encoding-length validation for locale strings (including LC_ALL semicolon-separated entries) before calling libc::setlocale.

Changes

Cohort / File(s)	Summary
CreateProcess null-byte validation `crates/vm/src/stdlib/winapi.rs`	Added runtime checks to reject embedded NUL (`\0`) characters in the optional `name` and `command_line` parameters; returns `cstring_error(vm)` on failure and aborts process creation before constructing C strings.
Windows locale validation for setlocale `crates/stdlib/src/locale.rs`	Added `MAX_CP_LEN` constant and Windows-only helpers `check_locale_name` and `check_locale_name_all`; validate encoding length (post-dot, optional `@` modifier) and iterate semicolon-separated locales for `LC_ALL` before calling `libc::setlocale`, returning an unsupported-locale error on invalid input.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Review null-byte checks in winapi.rs for both Some/None branches and ensure correct early return semantics and error construction.
Validate parsing logic in locale.rs (dot, @ modifier, semicolon splitting) and boundary cases near MAX_CP_LEN.
Confirm platform-conditional compilation and that non-Windows paths remain unchanged.
Test vectors: locales with/without encoding, with @ modifiers, semicolon lists, and embedded NULs in both affected APIs.

Poem

🐰 I hopped through code both neat and bright,
Found sneaky NULs and locales not right,
I nibble the bugs, I tidy the line,
Now CreateProcess and setlocale shine 🥕✨

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Title check	✅ Passed	The title 'Fix test_subprocess and locale' accurately reflects the main changes: runtime validation additions to CreateProcess for null bytes and Windows-specific locale encoding validation.

✨ Finishing touches

📝 Generate docstrings

🧪 Generate unit tests (beta)

Create PR with unit tests
Post copyable unit tests in a comment

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